Posterior dynamic stabilization in the treatment of lumbar degenerative disc disease: 2-year follow-up.

BACKGROUND: A prospective pilot study was designed to evaluate the role of a posterior dynamic stabilization technique in the surgical treatment of degenerative disc disease. Posterior dynamic stabilization with a hinged screw is a new concept in the surgical treatment of degenerative disc disease of the lumbar spine. The traditional surgical treatment is to apply a fusion procedure. However, numerous reports showed unsatisfactory clinical outcomes even when patients have satisfactory radiological outcomes following fusion procedures. MATERIAL AND METHODS: The study included patients who were surgically treated with a dynamic stabilization technique due to painful degenerative disc disease. Clinical and radiological findings for the 20 participating patients were analyzed in a 2-year follow-up study. Preoperative and postoperative data at the 3 (rd), 12 (th) and 24 (th) month were collected for both clinical and radiological outcomes. Statistical analyses between preoperative and postoperative data were performed using the Wilcoxon test. RESULTS: The clinical outcome measurements (VAS, ODI) showed significant improvement in all postoperative measurements compared to preoperative values. The mean preoperative visual analogue score (VAS, 7.9) and Oswestry Disability Index (ODI 59.2) significantly decreased to 0.8 for VAS and 9.2 for ODI, at 2 years post-operation (p<0.05). The radiological studies showed no significant changes between pre- and postoperative values, in all parameters. There was no mortality or morbidity. CONCLUSIONS: The results of this pilot study are encouraging. Dynamic stabilization may be an effective technique in the surgical treatment of painful degenerative disc disease. A larger series study, with longer follow-up periods and with control groups is needed to determine the success and safety of posterior dynamic stabilization in the surgical treatment of degenerative disc disease.

Endoscopic resection of a retroperitoneal schwannoma: case report.

INTRODUCTION: Retroperitoneal schwannomas are rare tumors. The symptoms are usually non-specific and these lesions can only be demonstrated with advanced radiological methods. Posterior and anterior approaches can be used to remove retroperitoneal schwannomas. Traditional techniques carry significant risks. CASE REPORT: A 35-year-old man was admitted with a history of right leg pain of 3 months duration. He had received conservative treatment and physical therapy but none of these measures had been helpful. Findings on physical and neurological examinations were all within normal limits. Magnetic resonance imaging revealed a retroperitoneal mass lesion medial to the right psoas muscle at the level of the S1 vertebra. The tumor was removed using an endoscopic transabdominal approach. CONCLUSION: The endoscopic transabdominal approach is a safe, efficient and minimally invasive procedure compared to traditional methods also to remove retroperitoneal schwannomas in selected cases.

Percutaneous endoscopic discectomy for far lateral lumbar disc herniations: prospective study and outcome of 66 patients.

BACKGROUND: Extraforaminal disc herniations represent up to 11% of all lumbar herniated discs. Numerous surgical approaches have been described. Percutaneous endoscopic discectomy (PED) is one of the minimally invasive techniques; after mastering this procedure it is a practical method that is used for treatment of foraminal or extraforaminal disc herniation. The outcome of PED for treatment of foraminal or extraforaminal disc herniation has been studied. METHOD: A total of 66 patients with foraminal or extraforaminal lumbar disc herniation was treated by applying the PED technique between January 1998 and June 2005. The positions of the herniated disc levels were L2-3 (n=5, 8%), L3-4 (n=19, 28%) and L4-5 (n=42; 64%). The selected patients had no previous surgery, appropriate conservative therapies were done before the operations, and MRI was the main diagnostic method with the clinical findings. Evaluation of the patients with clinical examinations, visual analogue pain scale (VAS) and Oswestry scale was performed preoperatively, on postoperative day 7 and in the postoperative 6-12 months period. RESULTS: In two patients (n=1, L4-5 and n=1, L3-4) disc material could not be removed with PED, so discectomy was performed with microscopic visualization during the same session. Three patients (n=3, L4-5) were reoperated on three to six months after primary surgery due to recurring disc problems with microscope visualization. In two patients (n=2, L4-5) root nerves were partially damaged, and in two patients (n=2, L4-5) root nerves were impinged by the working channel. These 4 patients had dysesthesias from just after surgery to a mean of 45 days after surgery. One of recurrent cases was among these patients. Neurological examinations showed minimal muscle weakness of the quadriceps femoris and diminished sensation of the L4 dermatomal area in patients with partial nerve root damage. This patient improved and the neurologic examination became normal with disappearance of the dysesthesia. There was no sign of reflex sympathetic dystrophy (RDS). With these two patients VAS and Oswestry scales scores decreased significantly early in the postoperative follow-up. The postoperative 6-month average scores are favourable in comparison with the average score at postoperative day 7. The postoperative 12-month scores showed no significant differences to those of postoperative month 1. CONCLUSION: Percutaneous endoscopic discectomy is a minimally invasive method and offers many benefits to the patient, but extensive surgical practice is needed to become a capable surgeon. Consequently this technique can only be a treatment option on appropriate patients. This study reconfirmed that the removal of fragmented disc material is achieved and offers a pain-free status.

Giant supratentorial atypical teratoid/rhabdoid tumor presentation: a case of a five-year-old child with favorable outcome and review of the literature.

Atypical teratoid/rhabdoid tumor of the central nervous system is a highly malignant neoplasm and that usually arises in the posterior fossa, survival from this is frequently poor. We present a unique case in a 21-month-old girl who had an atypical teratoid/rhabdoid tumor with cystic components located in the right fronto-parietal lobe. The patient underwent radical surgical intervention followed by chemotherapy. It consisted of five chemotherapeutic agents, but the patient did not receive any radiotherapy. The postoperative course was uneventful and the patient was followed-up by cranial magnetic resonance imaging every 3 months. Two years later at the last follow-up visit, there was no evidence of a tumor relapse on MRI, and the examination was symptom free. It is possible the favorable outcome of the patient resulted from a rapid diagnosis, prompt management, radical surgical intervention and aggressive chemotherapy.

Finite element model of the Jefferson fracture: comparison with a cadaver model.

This study tries to explain the reason why the Jefferson fracture is a burst fracture, using two different biomechanical models: a finite element model (FEM) and a cadaver model used to determine strain distribution in C1 during axial static compressive loading. For the FEM model, a three-dimensional model of C1 was obtained from a 29-year-old healthy human, using axial CT scans with intervals of 1.0 mm. The mesh model was composed of 8200 four-noded isoparametric tetrahedrons and 37,400 solid elements. The material properties of the cortical bone of the vertebra were assessed according to the previous literature and were assumed to be linear isotropic and homogeneous for all elements. Axial static compressive loads were applied at between 200 and 1200 N. The strain and stress (maximum shear and von Mises) analyses were determined on the clinically relevant fracture lines of anterior and posterior arches. The results of the FEM were compared with a cadaver model. The latter comprised the C1 bone of a cadaver placed in a methylmethacrylate foam. Axial static compressive loads between 200 and 1200 N were applied by an electrohydraulic testing machine. Strain values were measured using strain gauges, which were cemented to the bone where the clinically relevant fracture lines of the anterior and posterior arches were located. As a result, compressive strain was observed on the outer surface of the anterior arch and inferior surface of the posterior arch. In addition, there was tensile strain on the inner surface of the anterior arch and superior surface of the posterior arch. The strain values obtained from the two experimental models showed similar trends. The FEM analysis revealed that maximum strain changes occurred where the maximum shear and von Mises stresses were concentrated. The changes in the C1 strain and stress values during static axial loading biomechanically prove that the Jefferson fracture is a burst fracture.

Effects of cervical spine posture on axial load bearing ability: a biomechanical study.

OBJECT: The authors conducted a study to assess the effects of cervical posture on the loadbearing ability of the cervical spine. METHODS: Twelve cervical spine specimens obtained in 12 adult sheep were tested. The specimens were randomly separated into two groups. In Group I the specimens were fixed in a lordotic posture, and in Group II they were fixed in a straight posture. Axial compressive loads were applied at a constant rate of 5 cm/minute. Load-to-failure, time-to-failure, piston displacement at failure, and failure modes were recorded. Statistical analyses were performed to detect differences between the groups. There was no significant difference in load-to-failure values between the two groups. However, the time-to-failure and the piston displacement values for the straight spines were significantly less than those for the lordotic spines. Additionally, the straight spines failed predominantly through ventral elements, whereas the lordotic spines predominantly failed dorsally. CONCLUSIONS: It is concluded that a loss of a lordosis increases the risk of injury to the cervical spine following axial loading.

Effects of hole preparation on screw pullout resistance and insertional torque: a biomechanical study.

OBJECT: The authors conducted a study to assess the effect of a pilot hole preparation on screw pullout resistance and screw insertional torque. METHODS: Three different screws were tested: cancellous lateral mass screws, cortical lateral mass screws, and pedicle screws. Synthetic bone blocks were used as the host material. Each screw group was separated into two subgroups. The first subgroup of screws was inserted into the test material following pilot hole preparation. Pilot holes were prepared; a drill bit diameter size smaller than the core diameter of the screws was used. The second group of screws was inserted into the test material without pilot hole preparation (a 3- or 4-mm hole drilled for entrance site preparation only). The insertional torque was measured as the screw was advanced into the material. The screws were axially extracted from the host material at a constant speed of 2.5 mm/minute. The pullout resistances and insertional torques for the pilot hole and the nonpilot hole groups were then statistically compared. The authors found that preparation of a pilot hole caused a significant decrease in the insertional torque. The screws inserted without a pilot hole showed greater pullout resistances compared with those inserted following a pilot hole preparation; however, there was no statistically significant difference. CONCLUSIONS: The optimum screw insertion technique may involve drilling a short pilot hole and using a drill bit with a smaller diameter than the screw core diameter to increase bone-screw purchase. This applies to cancellous and cortical lateral mass screws as well as pedicle screws.

A new surgical technique: open-window corpectomy in the treatment of ossification of the posterior longitudinal ligament and advanced cervical spondylosis: technical note.

OBJECTIVE: To achieve satisfactory cervical spinal cord decompression with minimal removal of bone. METHODS: The open-window corpectomy technique is designed to remove a minimal amount of bone and achieve satisfactory decompression. With the use of a high-speed drill under a surgical microscope, only the dorsal surface of the corpus is removed after appropriate microdiscectomies. This leaves the anterior and the lateral portions of the vertebral corpus intact. RESULTS: In a 15-month period, a total of 11 patients were treated with this technique. Five patients improved, and the remaining six patients remained the same neurologically during a mean follow-up period of 8.3 months. No complications were observed in any patients. CONCLUSION: The open-window corpectomy provides satisfactory spinal cord decompression in a biomechanically sound manner.

Sylvian fissure lipomas: case reports and review of the literature.

Two patients with Sylvian fissure lipoma are reported. One of them was operated on because of an increased frequency of epileptic seizures in spite of high dose carbamazepine treatment. A review of the literature regarding the surgical experience with Sylvian lipomas revealed only four cases, and in none of them was the lipoma removed totally. One of ours is the first case in which total removal of the lipoma was achieved. The postoperative course was uneventful and carbamazepine dose was gradually lowered without further epileptic activity. If these exceedingly rare lesions cause symptoms then surgical intervention is indicated. With microsurgical techniques, Sylvian fissure lipomas can be removed totally without complication and symptomatic improvement may result.

Intraspinal schwannoma of the accessory nerve.

The second example of a schwannoma originating from the cervical portion of the accessory nerve is reported. The tumour was diagnosed by MRI and confirmed by surgery. The tumour was small and was located entirely within the cervical subarachnoid space without causing any detectable neurological deficit.

Traumatic intracranial carotid tree aneurysms.

OBJECTIVE: This study was designed to elucidate the requirements for angiographic evaluation in blunt head injuries, the timing of angiography, and the selection of appropriate therapeutic approaches. METHODS: Twelve cases of traumatic aneurysms (TAs) in the intracranial carotid tree were analyzed in this study. Neurological examination results, computed tomographic scans, pre- and postembolization cerebral angiograms, and follow-up data were included. RESULTS: In 11 of 12 cases, TAs were of cranial base origin; in 1 case, the aneurysm was located in the distal anterior cerebral artery. In seven of the cases with cranial base lesions, aneurysms were located in the intracavernous segment of the internal carotid artery; all of the computed tomographic scans for these cases demonstrated sphenoid sinus wall fractures and hematoma in the sphenoid sinus. In two cases, although the initial angiograms revealed no lesions, a second study performed 2 weeks later demonstrated the presence of aneurysms. Nine of the aneurysms were treated with endovascular techniques, two were managed conservatively, and the remaining one patient died with massive epistaxis while awaiting surgical treatment. No morbidity or additional permanent neurological deficits occurred in the endovascularly treated patient group. CONCLUSION: Patients with head trauma who present with sphenoid sinus fractures and massive epistaxis should be evaluated for the development of TAs as soon as possible. If the patients exhibit fractures without epistaxis, angiography should be deferred for 2 to 3 weeks; if the first angiographic evaluation reveals normal findings, repeated epistaxis should prompt a second angiographic evaluation. Current treatment of TAs involves occlusion of the main artery through the use of endovascular techniques. Cases involving internal carotid artery TAs of cranial base origin and patients who do not tolerate test occlusion require extracranial-to-intracranial bypass surgery.

Is it possible to recover from uncal herniation? Analysis of 71 head injured cases.

BACKGROUND: Uncal herniation (UH) caused by head trauma may become a fatal process if not treated rapidly. METHODS: We analysed the factors affecting the outcome in 71 surgically treated patients who had intracranial haematoma diagnosed by computerized tomography (CT), between January 1987 and June 1994 with the symptoms of UH. Age, incident-treatment interval, Glasgow Coma Scale (GCS), type of the lesion and the presence of polytrauma were correlated with Glasgow Outcome Scales (GOS) using SPSS PC+ statistical software. RESULTS: 49.3% of our patients were referred because of a fall from a height and 46.5% because of a motor vehicle accident. 12.7% of the patients were polytraumatized. The mean GCS of the series was 5.662. The mean GCS of the patients expired and who were in good recovery state were 4.8 and 6.9 respectively. Age, presence of polytrauma, type of the lesion and time interval between the incident and the treatment was found to be statistically insignificant when correlated with GOS. The correlation value between the GCS values and GOS was found to be highly significant (p < 0.00001). CONCLUSIONS: The findings showed that the degree of the herniation is the most important factor that affects the prognosis of the patients with UH. The reversibility of UH becomes more difficult if there are complications added during the grades of its progression but it may not be necessarily fatal and be reversible if appropriate interventions are rapidly performed.

Intracranial meningiomas in children: review of 29 cases.

BACKGROUND: Meningiomas are predominantly tumors of the fifth and sixth decades of life. Although rare in infancy and childhood, they represent an important field in pediatric neurosurgery. METHODS: Twenty-nine children under 15 years of age with intracranial meningiomas were treated during the period 1968-1994 in the Department of Pediatric Neurosurgery in Marseille (23 cases) and in the Department of Neurosurgery of Cerrahpasa Medical School in Istanbul (6 cases). These tumors represented 2.4% of all central nervous system (CNS) tumors in this age group. RESULTS: There were 18 boys and 11 girls. Eighteen cases (62%) occurred between 10 and 15 years of age and two cases were infants. Twelve children (41%) had associated neurofibromatosis. Presenting symptoms were related to the tumor location. Thirty-one intracranial meningiomas were observed in these 29 children. Cerebral convexity was the most common location and 13% of the tumors had no dural attachment. Thirty-one tumors were operated on and total removal was achieved in 25 patients (86.2%). Five patients died, one during surgery. There was no mortality among the 17 children without neurofibromatosis. After a mean 6.5 year follow-up period, 13 patients (45%) are neurologically intact, 8 patients (27.5%) have a moderate disability, without evidence of tumor recurrence. CONCLUSION: Childhood meningiomas occur predominantly in males. Absence of dural attachment is more common in children than in adults. Childhood meningiomas have a low recurrence rate. They are frequently associated with neurofibromatosis; this is the most important factor influencing outcome.

Successful outcome of aspergillus brain abscess in a patient who underwent bone marrow transplantation for aplastic anemia.

We report the course of an aspergillus brain abscess in an 18-year-old female patient who underwent bone marrow transplantation for aplastic anemia. The abscess was discovered on day 35 post-transplant, in a cranial computerized tomography (CT) scan performed for the evaluation of an unexplained headache. Meanwhile, she was receiving broad-spectrum antibacterials and liposomal amphotericin B for a right upper pulmonary lobe infiltrate. A percutaneous puncture of the cerebral lesion was performed; fungal elements were seen in the pus obtained and its culture yielded A. fumigatus. The dose of amphotericin B was increased, intraconazole was added and two more punctures were done. With these antifungals, the abscess regressed significantly; so, amphotericin B was discontinued after a cumulative dose of 6775 mg but intraconazole was maintained at 400 mg/day. At the last follow-up, seventeen months after detection of the abscess, the patient was well, without symptoms and the cerebral lesion diminished to a very small, thick-walled CT image.

Intramedullary tuberculous abscess: a case report.

STUDY DESIGN: This case report shows an intramedullary thoracic spinal cord abscess secondary to Mycobacterium tuberculosis in a 7-year-old boy with chronic progressive paraparesis and hypesthesia below T10. OBJECTIVES: The treatment of this patient involved drainage of pus followed by appropriate chemotherapy. SUMMARY OF BACKGROUND DATA: Abscess and tuberculomas of the spinal cord are rare entities. They are indistinguishable from neoplasms. The possibility of tubercular abscess or granuloma should be kept in mind when an intraspinal mass is found, provided that the clinical history is unusual for tumor. METHODS: A left T7-T8 hemilaminectomy was performed. A quantity of pus was drained through a small myelotomy. A small specimen was taken, and antituberculosis treatment was given after surgery. RESULTS: Excellent clinical outcome was obtained with a combination of medical and surgical management. CONCLUSION: The treatment of intramedullary abscess consists of surgical evacuation of the pus. Appropriate treatment offers a favorable prognosis even in cases with severe deficits.

Bilateral traumatic abducens nerve paralysis with cervical spine flexion injury.

Bilateral traumatic abducens nerve palsy is a rare condition. We report a case associated with cervical spine flexion injury. This may be the first such case report, as no similar case was found in our review of the literature. The mechanisms of injury in this case are relevant to theories that explain hyperextension injuries.

Craniopharyngioma extended into the posterior fossa.

A 7-year-old girl with a craniopharyngioma with a rare extension into the posterior fossa is presented. MRI revealed a solid calcified mass in the sellar and suprasellar region with a cyst expanded to the posterior fossa up to the foramen magnum and causing hydrocephalus and brainstem displacement. The tumor was removed totally with right pterional approach.